Research On Control Strategy Of Virtual Synchronous Generator In Microgrid

The irrational use of energy has led to environmental destruction.Many scholars are now studying renewable energy.Because distributed generation has the characteristics of flexibility,cleanliness and universality,it is one of the most promising micro power sources at this stage.But when it comes to the large power grid,it brings some other problems,such as not easy to control,the random volatility is relatively large,and then affects the stability of the system operation.Therefore,many scholars began to study the control strategy of inverter,and studied the strategy of virtual synchronous generator(VSG).This paper mainly studies the strategy based on VSG control.The characteristics of grid connected inverter under VSG control are studied.First,the power frequency modulation module and excitation regulation module under the control of VSG are set up,so that it can run independently under the condition of the grid and the isolated network,analyze the stability of the parameters under different conditions,and the frequency and voltage characteristics under the action of VSG control,and compare the traditional droop control through the MATLAB simulation.Secondly,a new control strategy,the constant voltage / constant frequency control of the island,and the control of the virtual synchronizer when the network is connected,can be used to solve the current and voltage shocks in the process of switching off the network.Finally,the effect of the adjustment coefficient,damping coefficient and moment of inertia on how the power frequency characteristics affect the stability of the system is described in detail.A simulation model is built based on Matlab/Simulink,and the correctness of VSG control is verified by experiments.The simulation results show that the VSG control strategy used in this paper can make the system more stable and apply to the micro grid,and improve the stability of the microgrid in the operation process.